Tamora tyre pressures?

[Ant.]

Running 18's but the handbook has pressures for 16's.....

What should they be? 24 allround?

[NCC]

24 all round works best for me. Last factory recommendation was 28 I think. Tried it and didn't like it one bit!

[shep1001]

NCC said:

24 all round works best for me. Last factory recommendation was 28 I think. Tried it and didn't like it one bit!

24 is good. 28 and it will jump about lie Zebedee on acid!

[Templedog]

23 front, 25 rear. Has anyone tried nitrogen in their tyres? Last track day I did the pressures were up over 30 after a couple of 6 lap sessions. Apparently nitrogen doesnt react as much to temperature?

[Kernow67]

Templedog said:

23 front, 25 rear. Has anyone tried nitrogen in their tyres? Last track day I did the pressures were up over 30 after a couple of 6 lap sessions. Apparently nitrogen doesnt react as much to temperature?

Stand by whilst I enter geek mode...

There are an awful lot of claims out there about nitrogen and tyre pressures, but IIRC, all gases pretty much behave like "ideal gases" when it comes to thermal expansion, so air and nitrogen will pretty much expand at the same rate. Coupled with the fact that air is 78% nitrogen, the difference will be even less. If it is any interest, the coefficient of thermal expansion for air is 0.0037/degree centigrade at standard temperature and pressure (zero degrees, 1 atmosphere), but does drop to 0.002 at 100 degrees C. Nope...I didn't think that would be of any interest.



[url]

[optimax sniffer]

If you doing track stuff the pressures will always go up. Rubber & brakes will heat the air / nitrogen.

Always check after the car has warmed up, and let the pressures down accordingly.

When you leave the track remember to raise them again

[Kernow67]

Just done a bit more reading and sifting the mad claims out.... best reason I can see to use nitrogen is that it doesn't contain water vapour like air does (less corrosion within the steel belts of the tyre...like I've ever suffered from that!) and it is largely inert (so won't fuel a fire like oxygen in air will if you have a really bad day on the track). Apparently it diffuses slower through a tyre than oxygen as well, so tyre pressures stay more constant over time, but honestly, thats got to take aaages.

F1 teams do use nitrogen, but I think this is because of the fire thing above, and also, as its a pure gas rather than a mixture, the tyre pressure will be much easier to predict at a certain temperature. But for them, that is critical, and won't affect a day on a track for a TVR.

I'll shut up with the geeky stuff now

[Templedog]

Cheers Gents, much appreciated.